Auditory Processing in Aphasia: Top Down or Bottom Up?
Pamela A. Smith, Ph.D., CCC-SLP
Thomas R. Zalewski, Ph.D., CCC-A
Bloomsburg University; Bloomsburg, PA
BACKGROUND
MATERIALS AND RESULTS
Adults with aphasia exhibit communication patterns that are in some ways
similar to individuals with auditory processing disorders. These individuals
exhibit syntactic and semantic deficits, difficulty processing longer/more
complex information, and impaired auditory comprehension in challenging
communicative environments.
STAGGERED SPONDIAC WORD (SSW) TEST
Psycholinguistic models of language processing in aphasia suggest the
presence of disruption in or between levels of representation, with
interruptions in the flow of information unidirectionally or bidirectionally.
Levels of processing include phonetic, phonemic, semantic, and syntactic.
APD TESTS
PERFORMANCE DISCUSSION
SSW - NOE Score
Both subjects were right handed, had posterior lesions and an absence of motor
involvement. Both subjects had normal hearing (Daisy: PTA R/L 10/10, SRT R/L 15/10;
Rose: PTA R/L 25/20, SRT R/L 20/15).
40
35
Four words are presented such as up stairs down town. In the Right
Ear First (REF) condition, up would be right non-competing(RNC), stairs
would be right competing(RC), down would be left competing (LC), and
town would be left non-competing (LNC). Subject repeats the words in
the order heard.
CID W-22 WORD RECOGNITION IN QUIET AND IN NOISE
TEST
30
25
Daisy
20
Rose
15
Normative
10
5
0
RNC
RC
LC
LNC
C-SSW Score
100
80
ASHA (1996) suggests that auditory processing skills are more “bottom up”
skills, (“What you do with what you hear” [Katz, 1992]); however,
architecturally, these models are similar to psycholinguistic processing
models that may include “top down” or larger contextual influences.
LANGUAGE: DAISY’s CAT profile revealed an auditory syntactic deficit as evidenced
by a significant difference in z scores between auditory sentence comprehension and written
sentence comprehension. Of note is that she comprehends paragraph length information in
the auditory modality better than sentence length information. She exhibits an ability to
utilize lexical information despite increased length of stimuli to heighten comprehension.
A list of words is presented to each ear in quiet and then with a +5 SNR.
Each ear’s results are then compared with the score in quiet vs. the score in
noise. Differences for each ear are then compared against one another to
determine if a large interaural difference exists.
60
Daisy
40
Rose
Normative
LANGUAGE: ROSE’s CAT profile revealed a difference in comprehension of written and
auditory information which was not statistically significant. Her comprehension scores
declined as level of complexity of the stimulus increased, an observation not seen with
Daisy.
20
AUDITORY PROCESSING: DAISY showed a LEFT ear preference for all CAP tasks.
This suggests a “reassignment” or “reallocation” of CAP functioning from the right ear,
which is generally the better ear in right handed individuals.
0
RNC
RC
LC
LNC
-20
COMPETING ENVIRONMENTAL SOUNDS TEST (CES)
CID W-22 in Quiet and Noise
PURPOSE
120%
Fourteen commonly heard sounds are presented. Each item consists of two
sounds presented in an overlapping fashion. The subject must identify the
two sounds that were heard either verbally or by pointing.
100%
80%
Daisy
60%
Rose
Normative
40%
To compare performance of patients with aphasia on a number of auditory
processing and language comprehension/production tools.
To determine any relationships between patient performance on these
measures with regard to levels of representation and auditory processing
skills.
20%
PITCH PATTERN SEQUENCE-ADULT VERSION
0%
Right
Left
Quiet
A series of three tones varying in frequency (pitch) are presented in the
same ear. Each ear is tested independently. The subject must identify the
pattern of the tones heard.
Right
Left
Noise
Competing Environmental Sounds
9
8
7
DICHOTIC DIGIT TEST
6
Daisy
5
Rose
To obtain preliminary data to drive further study regarding the relationship
between specific auditory processing skills and psycholinguistic functioning.
4
Normative
2
1
0
Right ear
Left ear
CONCLUSIONS/FUTURE DIRECTIONS
Pitch Pattern
Two different portions (low/high band pass) of a word are presented
simultaneously to each ear and the listener must repeat the fused word.
120
100
80
Daisy
Rose
60
Normative
COMPREHENSIVE APHASIA TEST
Auditory Processing Assessments: Staggered Spondaic Word Test, CID W22 words in quiet/noise, Competing Environmental Sounds Test, Pitch pattern
sequence, Dichotic digit test, and Binaural fusion
Aphasia Assessments: Comprehensive Aphasia Test
Five subjects were tested; 2 are compared here.
Both subjects underwent a preliminary pure tone audiometric threshold test to
assure candidacy for ongoing auditory processing testing.
Subjects were tested individually over 5-9 sessions by graduate students in
audiology and speech pathology with appropriate supervision by the
researchers.
CT scan results were obtained for both subjects.
40
20
0
This psycholinguistically based test consists of 34 subtests that comprise a
Cognitive Screen, Language Battery, and Disability Questionnaire. The
Language Battery categorizes subject performance in terms of deficits in
linguistic processing in the areas of comprehension of spoken language,
comprehension of written language, repetition, naming, reading, and
writing, based on differences in subtest z scores.
Hum
Dichotic Digits
100%
90%
Two subjects with similar sites of lesion and similar pure tone averages showed differing
patterns of auditory comprehension and auditory processing as measured on language tests
and auditory processing assessments. The differences in performance seem, at least in part,
related to selective patterns in reassignment of auditory processing skills from the lesioned
lobe to the contralateral non-disordered side. More complete reassignment appeared to result
in better integrative skills (“top down”)), but not better isolated syntactic skills. Daisy was able
to utilize semantic skills for paragraph comprehension and auditory processing tasks when
such tasks involved linguistic responses; however, performance was at chance for sentence
level syntactic tasks. Rose, who displayed incomplete APD temporal lobe reassignment, had
more difficulty utilizing lexical information to heighten her comprehension, relying more on a
“bottom-up” approach.
70%
60%
Daisy
50%
Rose
Normative
40%
30%
20%
10%
APHASIA TESTS
0%
Right ear
Comprehensive Aphasia Test
70
60
60
50
Daisy
40
40
Daisy
Rose
30
Rose
30
20
10
20
0
10
0
Words
Sentences
Auditory
Paragraphs
Words
Reading
Modality
Daisy
Rose
Normative
Left
30 dB SL
Results suggests that the auditory processing and linguistics systems involve components that
may be selectively impaired. It may be that this selective impairment contributes to
rehabilitative efforts, should spared abilities be identified and exploited. This should be
explored further in clinical/therapeutic tasks.
REFERENCES
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Right
Sentences
Left ear
Binaural Fusion
80
70
50
The support of the Faculty Professional Development Council of the Pennsylvania State
System of Higher Education is gratefully acknowledged.
Verbal
80%
Comprehension Scores - CAT
THANKS
SUMMARY: Daisy, who showed APD reassignment, had great difficulty overall with
auditory processing tasks, but performed particularly poorly on tasks that involved lesser
degrees of lexical access and/or utilization of contextual information (pitch pattern,
competing environmental sounds and dichotic digits). She performed better with tasks
involving integration, despite significant deficits in decoding. Rose, who showed
“incomplete reassignment,” also exhibited deficits in decoding, but had poorer integrative
ability than did Daisy; Rose did not show heightened auditory processing performance with
more complex linguistic stimuli.
3
Two numbers are presented to each ear at the same time; the subject
repeats the numbers heard. The order of repetition is not important.
BINAURAL FUSION
METHODS
AUDITORY PROCESSING: ROSE showed a different pattern in CAP tasks, with a
RIGHT ear preference for Dichotic Digits and Binaural Fusion and left ear preference for
the SSW, CES, and Pitch Pattern Sequence. She appears to be reassigning only SOME
functions to the lobe contralateral to the lesion.
Right
Left
American Speech-Language-Hearing Association (1996) Central auditory processing: Current status of research
and implications for clinical practice. American Journal of Audiology, 5, 41-54.
Katz, J. (1992) Classification of auditory processing disorders. In J. Katz, N. Stacker, & D. Henderson (Eds.)
Central Auditory Processing: A transdisciplinary view. St. Louis, MO: Mosby.
40 dB SL
Thanks to Kerry Cimino, Angela D’Angelis, Jill Foltz, Elizabeth Grippa, & Cindy McMillan
printed by
www.postersession.com